The rise in diabetes is, of course, linked to the rising rates of obesity across America. But what’s truly stunning is just how prevalent the disease has become, and how meteoric the growth rates are. Here’s what the country looks like on a county-by-county basis in 2004. The darker the color, the higher the incidence of diabetes:

[Click to visit interactive version]

Over at the interactive version, you can see that a few pockets of the U.S. have some astoundingly high incidence rates — well over 10% in several counties in Mississippi, for example. Though it seems like the hardest hit areas are rural, you can also see alarmingly high rates in the suburbs around big cities such as Atlanta and Dallas. But it gets worse. Here’s the data in 2006:

And just two years later, in 2008:

[Click to see interactive version]

There are huge patches where diabetes runs above 12.5% across multiple counties, and even in cities such as Houston, rates are above 10%. By now, a clear pattern is emerging: Diabetes is spreading like a virus across the south and Appalachia, across regions known for weak economies. The map is perhaps the most bracing confirmation possible that low incomes and diabetes develop in lockstep.